Photographing optical lens assembly, image capturing unit and electronic device

ABSTRACT

A photographing optical lens assembly includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element and a sixth lens element. The first lens element with positive refractive power has an object-side surface being convex in a paraxial region thereof. The second lens element has negative refractive power. The third lens element has refractive power. The fourth lens element with refractive power has an image-side surface being concave in a paraxial region thereof. The fifth lens element with negative refractive power has an object-side surface being concave in a paraxial region thereof and an image-side surface being convex in a paraxial region thereof. The sixth lens element with negative refractive power has an image-side surface being concave in a paraxial region thereof.

RELATED APPLICATIONS

This application claims priority to Taiwan Application 103142463, filed Dec. 5, 2014, which is incorporated by reference herein in its entirety.

BACKGROUND

Technical Field

The present disclosure relates to a photographing optical lens assembly, an image capturing unit and an electronic device, more particularly to a photographing optical lens assembly and an image capturing unit applicable to an electronic device.

Description of Related Art

In recent years, with the popularity of electronic devices having camera functionalities, the demand of miniaturized optical systems has been increasing. The sensor of a conventional optical system is typically a CCD (Charge-Coupled Device) or a CMOS (Complementary Metal-Oxide-Semiconductor) sensor. As the advanced semiconductor manufacturing technologies have allowed the pixel size of sensors to be reduced and compact optical systems have gradually evolved toward the field of higher megapixels, there is an increasing demand for compact optical systems featuring better image quality.

A conventional optical system employed in a portable electronic product mainly adopts a five-element lens structure. Due to the popularity of mobile terminals with high-end specifications, such as smart phones, tablet personal computers and wearable apparatus, the requirements for high resolution and image quality of present compact optical systems increase significantly. However, the conventional optical systems cannot satisfy these requirements of the compact optical systems.

Other conventional compact optical systems with six-element lens structure are developed to enhance resolution and image quality. However, a back focal length of the optical system is too long to favorably keep the optical system compact. Furthermore, the refractive power of the optical system is unevenly distributed, which overly enlarges the incident angle of the light at the peripheral region of the image, thereby resulting in excessive stray light. Moreover, an image-side surface of the fourth lens element of the optical system is convex. Hence, it is unfavorable for adjusting the image difference between a central region and a peripheral region and reducing the aberration at the peripheral region of the image.

SUMMARY

According to one aspect of the present disclosure, a photographing optical lens assembly includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, and a sixth lens element. The first lens element with positive refractive power has an object-side surface being convex in a paraxial region thereof. The second lens element has negative refractive power. The third lens element has refractive power. The fourth lens element with refractive power has an image-side surface being concave in a paraxial region thereof. The fifth lens element with negative refractive power has an object-side surface being concave in a paraxial region thereof and an image-side surface being convex in a paraxial region thereof, wherein both of the object-side surface and the image-side surface of the fifth lens element are aspheric. The sixth lens element with negative refractive power has an image-side surface being concave in a paraxial region thereof, wherein both of an object-side surface and the image-side surface of the sixth lens element are aspheric, and the image-side surface of the sixth lens element has at least one inflection point. The photographing optical lens assembly has a total of six lens elements with refractive power. The photographing optical lens assembly further comprises an aperture stop located between an imaged object and the third lens element. When a curvature radius of the image-side surface of the fourth lens element is R8, a focal length of the photographing optical lens assembly is f, an axial distance between the aperture stop and an image surface is SL, an axial distance between the object-side surface of the first lens element and the image surface is TL, a focal length of the fifth lens element is f5, a focal length of the sixth lens element is f6, the following conditions are satisfied: 0.3<R8/f; 0.65<SL/TL<1.2; and 0<f5/f6.

According to another aspect of the present disclosure, a photographing optical lens assembly includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, and a sixth lens element. The first lens element has positive refractive power. The second lens element with negative refractive power has an image-side surface being concave in a paraxial region thereof. The third lens element has refractive power. The fourth lens element with refractive power has an image-side surface being concave in a paraxial region thereof. The fifth lens element has negative refractive power, wherein both of an object-side surface and an image-side surface of the fifth lens element are aspheric. The sixth lens element with negative refractive power has an image-side surface being concave in a paraxial region thereof, wherein both of an object-side surface and the image-side surface of the sixth lens element are aspheric, and the image-side surface of the sixth lens element has at least one inflection point. The photographing optical lens assembly has a total of six lens elements with refractive power. The photographing optical lens assembly further comprises an aperture stop located between an imaged object and the second lens element. An air gap in a paraxial region is located between every two of the first lens element, the second lens element, the third lens element, the fourth lens element, the fifth lens element and the sixth lens element that are adjacent to each other. When a curvature radius of the image-side surface of the fourth lens element is R8, a focal length of the photographing optical lens assembly is f, an axial distance between the aperture stop and an image surface is SL, an axial distance between an object-side surface of the first lens element and the image surface is TL, an Abbe number of the second lens element is V2, an Abbe number of the fifth lens element is V5, the following conditions are satisfied: 0.3<R8/f; 0.85<SL/TL<1.2; and 0.70<V2/V5.

According to still another aspect of the present disclosure, an image capturing unit includes the aforementioned photographing optical lens assembly and an image sensor, wherein the image sensor is disposed on the image side of the photographing optical lens assembly.

According to yet another aspect of the present disclosure, an electronic device includes the aforementioned image capturing unit.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure can be more fully understood by reading the following detailed description of the embodiments, with reference made to the accompanying drawings as follows:

FIG. 1 is a schematic view of an image capturing unit according to the 1st embodiment of the present disclosure;

FIG. 2 shows spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 1st embodiment;

FIG. 3 is a schematic view of an image capturing unit according to the 2nd embodiment of the present disclosure;

FIG. 4 shows spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 2nd embodiment;

FIG. 5 is a schematic view of an image capturing unit according to the 3rd embodiment of the present disclosure;

FIG. 6 shows spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 3rd embodiment;

FIG. 7 is a schematic view of an image capturing unit according to the 4th embodiment of the present disclosure;

FIG. 8 shows spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 4th embodiment;

FIG. 9 is a schematic view of an image capturing unit according to the 5th embodiment of the present disclosure;

FIG. 10 shows spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 5th embodiment;

FIG. 11 is a schematic view of an image capturing unit according to the 6th embodiment of the present disclosure;

FIG. 12 shows spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 6th embodiment;

FIG. 13 is a schematic view of an image capturing unit according to the 7th embodiment of the present disclosure;

FIG. 14 shows spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 7th embodiment;

FIG. 15 is a schematic view of an image capturing unit according to the 8th embodiment of the present disclosure;

FIG. 16 shows spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 8th embodiment;

FIG. 17 is a schematic view of Yk42 of a fourth lens element and Yc62 of a sixth lens element in FIG. 1;

FIG. 18 shows an electronic device according to one embodiment;

FIG. 19 shows an electronic device according to another embodiment; and

FIG. 20 shows an electronic device according to still another embodiment.

DETAILED DESCRIPTION

A photographing optical lens assembly includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element and a sixth lens element. The photographing optical lens assembly has a total of six lens elements with refractive power.

According to the photographing optical lens assembly of the present disclosure, in some embodiments, an air gap in a paraxial region is arranged between every two of the first lens element, the second lens element, the third lens element, the fourth lens element, the fifth lens element and the sixth lens element that are adjacent to each other, that is, each of the first through sixth lens elements of the photographing optical lens assembly can be a single and non-cemented lens element. Moreover, the manufacturing process of the cemented lenses is more complex than the non-cemented lenses. In particular, an image-side surface of one lens element and an object-side surface of the following lens element need to have accurate curvature to ensure these two lens elements will be highly cemented. However, during the cementing process, those two lens elements might not be highly cemented due to displacement and it is thereby not favorable for the image quality of the photographing optical lens assembly. Therefore, there is an air gap in a paraxial region between every two of the first lens element, the second lens element, the third lens element, the fourth lens element, the fifth lens element and the sixth lens element that are adjacent to each other in the present disclosure for solving the problem generated by the cemented lens elements.

The first lens element has positive refractive power. The first lens element can have an object-side surface being convex in a paraxial region thereof and an image-side surface being concave in a paraxial region thereof. Therefore, the first lens element provides the photographing optical lens assembly with the positive refractive power as the photographing optical lens assembly needs to be. Furthermore, it is favorable for properly adjusting a total track length of the photographing optical lens assembly.

The second lens element has negative refractive power. The second lens element can have an object-side surface being convex in a paraxial region thereof and an image-side surface being concave in a paraxial region thereof. Therefore, it is favorable for correcting the aberration from the first lens element. Furthermore, it is favorable for correcting the astigmatism of the photographing optical lens assembly so as to improve the image quality.

The third lens element can have positive refractive power. The third lens element can have an image-side surface being convex in a paraxial region thereof. Therefore, it is favorable for further reducing the sensitivity of the photographing optical lens assembly and correcting the spherical aberration of the photographing optical lens assembly.

The fourth lens element can have positive refractive power. The fourth lens element can have an object-side surface being convex in a paraxial region thereof. The fourth lens element has an image-side surface being concave in a paraxial region thereof, and the image-side surface of the fourth lens element can have at least one convex shape in an off-axis region thereof. Furthermore, the image-side surface of the fourth lens element can have at least one critical point k. A projection of the critical point k on an optical axis is closer to the image side of the photographing optical lens assembly than an intersection of the image-side surface of the fourth lens element and the optical axis. Therefore, it is favorable for balancing the focusing capabilities at the central region and the off-axis region so as to reduce the image difference between the central region and the peripheral region.

The fifth lens element with negative refractive power can have an object-side surface being concave in a paraxial region thereof and an image-side surface being convex in a paraxial region thereof. Therefore, it is favorable for correcting the astigmatism of the photographing optical lens assembly so as to improve the image quality.

The sixth lens element with negative refractive power can have an object-side surface being convex in a paraxial region thereof. The sixth lens element has and an image-side surface being concave in a paraxial region thereof. The image-side surface of the sixth lens element has at least one inflection point. The object-side surface of the sixth lens element can have at least one concave shape and at least one convex shape in an off-axis region thereof. The object-side surface of the sixth lens element can change from the convex shape to the concave shape and then the convex shape in sequence along a direction from the paraxial region thereof toward the off-axis region thereof (That is, the object-side surface of the sixth lens element, in order from the paraxial region to the off-axis region, can have the convex shape, the concave shape and another convex shape). Therefore, the sixth lens element and the fifth lens element having negative refractive powers are favorable for the principal point of the photographing optical lens assembly being positioned away from the image side of the photographing optical lens assembly so as to reduce a back focal length of the photographing optical lens assembly, thereby keeping a compact size thereof. Furthermore, it is favorable for evenly distributing the refractive powers of the photographing optical lens assembly so as to avoid excessive incident angle of the light at the peripheral region of the image, thereby reducing stray light.

When a curvature radius of the image-side surface of the fourth lens element is R8, a focal length of the photographing optical lens assembly is f, the following condition is satisfied: 0.3<R8/f. Therefore, it is favorable for correcting the Petzval sum of the photographing optical lens assembly so as to improve the flatness of the image surface and reduce the astigmatism and the coma of the off-axis field. Preferably, the following condition is satisfied: 0.5<R8/f.

The photographing optical lens assembly further comprises an aperture stop. When an axial distance between the aperture stop and an image surface is SL, an axial distance between the object-side surface of the first lens element and the image surface is TL, the following condition is satisfied: 0.65<SL/TL<1.2. Therefore, it is favorable for reducing the total track length of photographing optical lens assembly so as to keep the photographing optical lens assembly compact. Preferably, the following condition is satisfied: 0.85<SL/TL<1.2.

When a focal length of the fifth lens element is f5, a focal length of the sixth lens element is f6, the following condition is satisfied: 0<f5/f6. Therefore, it is favorable for avoiding overloading the refractive power on a single lens element so as to avoid excessive aberration. Furthermore, it is favorable for the principal point of the photographing optical lens assembly being further positioned away from the image side of the photographing optical lens assembly so as to reduce the back focal length of the photographing optical lens assembly, thereby keeping a compact size thereof. Preferably, the following condition is satisfied: 0.1<f5/f6<10.

When an Abbe number of the second lens element is V2, an Abbe number of the fifth lens element is V5, the following condition is satisfied: 0.70<V2/V5. Therefore, it is favorable for correcting the chromatic aberration of the photographing optical lens assembly.

When the curvature radius of the image-side surface of the fourth lens element is R8, the focal length of the photographing optical lens assembly is f, an Abbe number of the first lens element is V1, the Abbe number of the fifth lens element is V5, the following condition can be satisfied: 0<R8/[f*(V1−V5)]<3. Therefore, the Abbe number of the fifth lens element, the curvature radius of the image-side surface of the fourth lens element and the Abbe number of the first lens element are properly arranged, so that it is favorable for balancing the aberration of the photographing optical lens assembly.

When a curvature radius of the object-side surface of the third lens element is R5, a curvature radius of the image-side surface of the third lens element is R6, the curvature radius of the image-side surface of the fourth lens element is R8, the following condition can be satisfied: 0<R8/(|R5|−|R6|)<2.45. Therefore, it is favorable for correcting the spherical aberration of the photographing optical lens assembly.

When an axial distance between the first lens element and the second lens element is T12, an axial distance between the second lens element and the third lens element is T23, an axial distance between the third lens element and the fourth lens element is T34, an axial distance between the fourth lens element and the fifth lens element is T45, an axial distance between the fifth lens element and the sixth lens element is T56, the following conditions can be satisfied: 0<T12<T34<T23<T45; and 0<T12<T56<T23<T45. Therefore, it is favorable for properly adjusting the axial distances between every two adjacent lens elements so as to reduce the total track length of the photographing optical lens assembly, thereby further keeping a compact size thereof.

When a vertical distance between a non-axial critical point on the image-side surface of the sixth lens element and the optical axis is Yc62, the focal length of the photographing optical lens assembly is f, the following condition can be satisfied: 0.1<Yc62/f<0.7. Therefore, it is favorable for the principal point of the photographing optical lens assembly being further positioned away from the image side of the photographing optical lens assembly so as to reduce the total track length of the photographing optical lens assembly. Furthermore, it is favorable for effectively reducing the incident angle of the light projecting onto the image sensor, so that it is favorable for improving the image-sensing efficiency of the image sensor and further correcting the aberration of the off-axis field. As seen in FIG. 17, FIG. 17 shows a schematic view of Yc62 of a sixth lens element in FIG. 1, the critical point on the image-side surface of the sixth lens element is a non-axial point on the image-side surface of the sixth lens element where its tangent is perpendicular to the optical axis. Specifically, the critical points mentioned above are not located on the optical axis.

According to the photographing optical lens assembly of the present disclosure, the image-side surface of the fourth lens element can have at least one critical point k. The projection of the critical point k on the optical axis is closer to the image side of the photographing optical lens assembly than the intersection of the image-side surface of the fourth lens element and the optical axis (That is, an axial distance between the projection of the critical point k on the optical axis and the image side thereof is shorter than an axial distance between aforementioned intersection and the image side thereof). When a vertical distance between the critical point k on the image-side surface of the fourth lens element and the optical axis is Yk42, the focal length of the fifth lens element is f5, the following condition can be satisfied: −1.0<Yk42/f5<0. Therefore, it is favorable for effectively reducing the incident angle of the light projecting onto the image sensor so as to correct the aberration of the off-axis field. As seen in FIG. 17, FIG. 17 shows a schematic view of critical point k and Yk42 of a fourth lens element in FIG. 1.

When the axial distance between the object-side surface of the first lens element and the image surface is TL, a maximum image height of the photographing optical lens assembly (half of a diagonal length of an effective photosensitive area of an image sensor) is ImgH, the following condition can be satisfied: TL/ImgH<2.0. Therefore, it is favorable for keeping the photographing optical lens assembly compact so as to be equipped in an electronic device.

When the curvature radius of the image-side surface of the fourth lens element is R8, a curvature radius of the object-side surface of the fifth lens element is R9, the following condition can be satisfied: −19<R8/R9<0. Therefore, the curvatures of the fourth lens element and the fifth lens element are properly arranged, so that it is favorable for further correcting the astigmatism of the photographing optical lens assembly so as to increase the image quality at the peripheral region of the image.

When a central thickness of the first lens element is CT1, a central thickness of the second lens element is CT2, a central thickness of the third lens element is CT3, a central thickness of the fourth lens element is CT4, a central thickness of the fifth lens element is CT5, a central thickness of the sixth lens element is CT6, the following conditions can be satisfied: CT2, CT4, CT5<CT1, CT3; and CT1, CT3 <CT6 (That is, each of the central thickness of the first lens element and the central thickness of the third lens element is greater than each of the central thickness of the second lens element, the central thickness of the fourth lens element and the central thickness of the fifth lens element. In addition, the central thickness of the sixth lens element is greater than each of the central thickness of the first lens element and the central thickness of the third lens element). Therefore, it is favorable for properly adjusting the thicknesses of the lens elements so as to prevent the lens elements from unfavorable molding problems, thereby the thicknesses of the lens elements are more homogeneous.

When a focal length of the first lens element is f1, a focal length of the third lens element is f3, the following condition can be satisfied: 0.1<|f1/f3|. Therefore, it is favorable for balancing the arrangement of the refractive powers of the lens elements so as to avoid excessive spherical aberration and effectively reduce the sensitivity of the photographing optical lens assembly.

According to the photographing optical lens assembly of the present disclosure, an aperture stop can be configured as a front stop or a middle stop. A front stop disposed between an imaged object and the first lens element can provide a longer distance between an exit pupil of the photographing optical lens assembly and the image surface and thereby improves the image-sensing efficiency of an image sensor (for example, CCD or CMOS). A middle stop disposed between the first lens element and the image surface is favorable for enlarging the view angle of the photographing optical lens assembly and thereby provides a wider field of view for the same.

According to the photographing optical lens assembly of the present disclosure, the lens elements thereof can be made of glass or plastic material. When the lens elements are made of glass material, the distribution of the refractive power of the photographing optical lens assembly may be more flexible to design. When the lens elements are made of plastic material, the manufacturing cost can be effectively reduced. Furthermore, surfaces of each lens element can be arranged to be aspheric, since the aspheric surface of the lens element is easy to form a shape other than spherical surface so as to have more controllable variables for eliminating the aberration thereof, and to further decrease the required number of the lens elements. Therefore, the total track length of the photographing optical lens assembly can also be reduced.

According to the photographing optical lens assembly of the present disclosure, each of an object-side surface and an image-side surface has a paraxial region and an off-axis region. The paraxial region refers to the region of the surface where light rays travel close to the optical axis, and the off-axis region refers to the region of the surface away from the paraxial region. Particularly, when the lens element has a convex surface, it indicates that the surface is convex in the paraxial region thereof; when the lens element has a concave surface, it indicates that the surface is concave in the paraxial region thereof. Moreover, when a region of refractive power or focus of a lens element is not defined, it indicates that the region of refractive power or focus of the lens element is in the paraxial region thereof.

According to the photographing optical lens assembly of the present disclosure, an image surface of the photographing optical lens assembly, based on the corresponding image sensor, can be flat or curved, especially a curved surface being concave facing towards the object side of the photographing optical lens assembly.

According to the photographing optical lens assembly of the present disclosure, the photographing optical lens assembly can include at least one stop, such as an aperture stop, a glare stop or a field stop. Said glare stop or said field stop is set for eliminating the stray light and thereby improving the image quality thereof.

According to the present disclosure, an image capturing unit is provided. The image capturing unit includes the photographing optical lens assembly according to the aforementioned photographing optical lens assembly of the present disclosure, and an image sensor, wherein the image sensor is disposed on the image side of the aforementioned photographing optical lens assembly, that is, the image sensor can be disposed on or near an image surface of the aforementioned photographing optical lens assembly. In some embodiments, the image capturing unit can further include a barrel member, a holding member or a combination thereof.

In FIG. 18, FIG. 19 and FIG. 20, an image capturing device 10 may be installed in, but not limited to, an electronic device, including a smart phone (FIG. 18), a tablet personal computer (FIG. 19) or a wearable device (FIG. 20). The three figures of different kinds of electronic device are only exemplary for showing the image capturing device of present disclosure installing in an electronic device and is not limited thereto. In some embodiments, the electronic device can further include, but not limited to, a display unit, a control unit, a storage unit, a random access memory unit (RAM), a read only memory unit (ROM) or a combination thereof.

According to the photographing optical lens assembly of the present disclosure, the photographing optical lens assembly can be optionally applied to moving focus optical systems. Furthermore, the photographing optical lens assembly is featured with good capability in the correction of aberration and high image quality, and can be applied to 3D (three-dimensional) image capturing applications, in products such as digital cameras, mobile devices, digital tablets, wearable devices, smart televisions, wireless monitoring devices, motion sensing input devices, driving recorders, rear view cameras and other electronic imaging devices. According to the above description of the present disclosure, the following specific embodiments are provided for further explanation.

1st Embodiment

FIG. 1 is a schematic view of an image capturing unit according to the 1st embodiment of the present disclosure. FIG. 2 shows, in order from left to right, spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 1st embodiment. In FIG. 1, the image capturing unit includes the photographing optical lens assembly (its reference numeral is omitted) of the present disclosure and an image sensor 190. The photographing optical lens assembly includes, in order from an object side to an image side, an aperture stop 100, a first lens element 110, a second lens element 120, a third lens element 130, a fourth lens element 140, a fifth lens element 150, a sixth lens element 160, an IR-cut filter 170 and an image surface 180, wherein the photographing optical lens assembly has a total of six non-cemented lens elements (110-160) with refractive power. There is an air gap in a paraxial region between every two of the first lens element 110, the second lens element 120, the third lens element 130, the fourth lens element 140, the fifth lens element 150 and the sixth lens element 160 that are adjacent to each other.

The first lens element 110 with positive refractive power has an object-side surface 111 being convex in a paraxial region thereof and an image-side surface 112 being convex in a paraxial region thereof. The first lens element 110 is made of plastic material and has the object-side surface 111 and the image-side surface 112 being both aspheric.

The second lens element 120 with negative refractive power has an object-side surface 121 being convex in a paraxial region thereof and an image-side surface 122 being concave in a paraxial region thereof. The second lens element 120 is made of plastic material and has the object-side surface 121 and the image-side surface 122 being both aspheric.

The third lens element 130 with positive refractive power has an object-side surface 131 being concave in a paraxial region thereof and an image-side surface 132 being convex in a paraxial region thereof. The third lens element 130 is made of plastic material and has the object-side surface 131 and the image-side surface 132 being both aspheric.

The fourth lens element 140 with positive refractive power has an object-side surface 141 being convex in a paraxial region thereof and an image-side surface 142 being concave in a paraxial region thereof. The fourth lens element 140 is made of plastic material and has the object-side surface 141 and the image-side surface 142 being both aspheric. The image-side surface 142 of the fourth lens element 140 has at least one convex shape in an off-axis region thereof.

The fifth lens element 150 with negative refractive power has an object-side surface 151 being concave in a paraxial region thereof and an image-side surface 152 being convex in a paraxial region thereof. The fifth lens element 150 is made of plastic material and has the object-side surface 151 and the image-side surface 152 being both aspheric.

The sixth lens element 160 with negative refractive power has an object-side surface 161 being convex in a paraxial region thereof and an image-side surface 162 being concave in a paraxial region thereof. The sixth lens element 160 is made of plastic material and has the object-side surface 161 and the image-side surface 162 being both aspheric. The image-side surface 162 of the sixth lens element 160 has at least one inflection point. The object-side surface 161 of the sixth lens element 160 has at least one concave shape and at least one convex shape in an off-axis region thereof. The object-side surface 161 of the sixth lens element 160 changes from the convex shape to the concave shape and then the convex shape in order from the paraxial region thereof toward the off-axis region thereof.

The IR-cut filter 170 is made of glass and located between the sixth lens element 160 and the image surface 180, and will not affect the focal length of the photographing optical lens assembly. The image sensor 190 is disposed on or near the image surface 180 of the photographing optical lens assembly.

The equation of the aspheric surface profiles of the aforementioned lens elements of the 1st embodiment is expressed as follows: X(Y)=(Y ² /R)/(1+sqrt(1−(1+k)×(Y/R)²))+Σ(Ai)×(Y ^(i)),

where,

X is the relative distance between a point on the aspheric surface spaced at a distance Y from an optical axis and the tangential plane at the aspheric surface vertex on the optical axis;

Y is the vertical distance from the point on the aspheric surface to the optical axis;

R is the curvature radius;

k is the conic coefficient; and

Ai is the i-th aspheric coefficient, and in the embodiments, i may be, but is not limited to, 4, 6, 8, 10, 12, 14 and 16.

In the photographing optical lens assembly of the image capturing unit according to the 1st embodiment, when a focal length of the photographing optical lens assembly is f, an f-number of the photographing optical lens assembly is Fno, and half of a maximal field of view of the photographing optical lens assembly is HFOV, these parameters have the following values: f=4.33 millimeters (mm); Fno=2.20; and HFOV=32.1 degrees.

When an Abbe number of the second lens element 120 is V2, an Abbe number of the fifth lens element 150 is V5, the following condition is satisfied: V2/V5=1.00.

When a curvature radius of the image-side surface 142 of the fourth lens element 140 is R8, the focal length of the photographing optical lens assembly is f, the following condition is satisfied: R8/f=0.72.

When the curvature radius of the image-side surface 142 of the fourth lens element 140 is R8, a curvature radius of the object-side surface 151 of the fifth lens element 150 is R9, the following condition is satisfied: R8/R9=−2.02.

When the curvature radius of the image-side surface 142 of the fourth lens element 140 is R8, the focal length of the photographing optical lens assembly is f, an Abbe number of the first lens element 110 is V1, the Abbe number of the fifth lens element 150 is V5, the following condition is satisfied: R8/[f*(V1−V5)]=0.02.

When a curvature radius of the object-side surface 131 of the third lens element 130 is R5, a curvature radius of the image-side surface 132 of the third lens element 130 is R6, the curvature radius of the image-side surface 142 of the fourth lens element 140 is R8, the following condition is satisfied: R8/(|R5|+|R6|)=0.53.

When a vertical distance between a critical point k on the image-side surface 142 of the fourth lens element 140 and an optical axis is Yk42, a focal length of the fifth lens element 150 is f5, the following condition is satisfied: Yk42/f5=−0.05.

When a vertical distance between a non-axial critical point on the image-side surface 162 of the sixth lens element 160 and the optical axis is Yc62, the focal length of the photographing optical lens assembly is f, the following condition is satisfied: Yc62/f=0.25.

When a focal length of the first lens element 110 is f1, a focal length of the third lens element 130 is f3, the following condition is satisfied: |f|/f3|=0.18.

When the focal length of the fifth lens element 150 is f5, a focal length of the sixth lens element 160 is f6, the following condition is satisfied: f5/f6=1.23.

When an axial distance between the aperture stop 100 and the image surface 180 is SL, an axial distance between the object-side surface 111 of the first lens element 110 and the image surface 180 is TL, the following condition is satisfied: SL/TL=0.95.

When the axial distance between the object-side surface 111 of the first lens element 110 and the image surface 180 is TL, a maximum image height of the photographing optical lens assembly is ImgH, the following condition is satisfied: TL/ImgH=1.81.

The detailed optical data of the 1st embodiment are shown in Table 1 and the aspheric surface data are shown in Table 2 below.

TABLE 1 1st Embodiment f = 4.33 mm, Fno = 2.20, HFOV = 32.1 deg. Focal Surface # Curvature Radius Thickness Material Index Abbe # Length 0 Object Plano Infinity 1 Ape. Stop Plano −0.237 2 Lens 1 1.855 (ASP) 0.561 Plastic 1.535 55.7 2.93 3 −9.019 (ASP) 0.030 4 Lens 2 2.105 (ASP) 0.240 Plastic 1.650 21.4 −5.65 5 1.278 (ASP) 0.346 6 Lens 3 −3.334 (ASP) 0.457 Plastic 1.530 55.8 16.04 7 −2.509 (ASP) 0.021 8 Lens 4 2.403 (ASP) 0.256 Plastic 1.544 55.9 17.01 9 3.123 (ASP) 0.258 10 Lens 5 −1.548 (ASP) 0.489 Plastic 1.650 21.4 −18.76 11 −1.994 (ASP) 0.445 12 Lens 6 2.281 (ASP) 0.538 Plastic 1.530 55.8 −15.25 13 1.634 (ASP) 0.700 14 IR-cut filter Plano 0.210 Glass 1.517 64.2 — 15 Plano 0.523 16 Image Plano — Note: Reference wavelength is 587.6 nm (d-line),

TABLE 2 Aspheric Coefficients Surface # 2 3 4 5 6 7 k = −2.4590E−01 −9.0000E+01 −1.2615E+01 −3.8549E+00 −4.1326E+01  −2.1711E+01 A4 = −1.8945E−05 −3.2886E−02 −4.7884E−02 −2.6848E−02 1.4211E−02 −7.3659E−02 A6 = −6.2094E−03  1.0465E−01  6.3203E−02 −7.9173E−03 −4.4109E−02   4.7860E−02 A8 =  3.8345E−03 −1.4585E−01 −1.0332E−02  1.1077E−01 7.6527E−02  4.7931E−02 A10 = −6.3266E−02  1.9972E−02 −1.0813E−01 −2.3653E−01 7.5126E−03 −1.9401E−02 A12 =  9.4009E−02  4.3283E−02  5.1147E−02  1.4616E−01 2.0244E−03  3.2500E−03 A14 = −5.8433E−02 −2.8830E−02  1.1229E−02 −1.2848E−02 — — Surface # 8 9 10 11 12 13 k = −4.7161E+00 −6.6469E+00 −7.9572E+00 −5.9912E−01 −6.1347E+00 −6.5357E+00 A4 = −1.3628E−01 −5.1368E−02  1.9576E−02  8.8923E−02 −1.9757E−01 −1.1121E−01 A6 = −7.4680E−03 −4.2785E−02 −2.6742E−02 −4.7282E−02  9.4988E−02  3.6453E−02 A8 =  6.4602E−03  5.0975E−03  8.5962E−02  3.1665E−02 −6.4935E−02 −1.4221E−02 A10 = −6.5700E−02  8.7719E−03 −4.8001E−02  1.0429E−02  3.8628E−02  4.4849E−03 A12 =  1.9689E−02 −6.0531E−03  7.1044E−03 −4.8899E−03 −1.2251E−02 −9.0047E−04 A14 =  6.3824E−02  1.7198E−03  3.3272E−03 −3.9490E−03  1.8969E−03  1.0066E−04 A16 = −6.7805E−02 — −2.5200E−03  1.3597E−03 −1.1476E−04 −5.0811E−06

In Table 1, the curvature radius, the thickness and the focal length are shown in millimeters (mm). Surface numbers 0-16 represent the surfaces sequentially arranged from the object-side to the image-side along the optical axis. In Table 2, k represents the conic coefficient of the equation of the aspheric surface profiles. A4-A16 represent the aspheric coefficients ranging from the 4th order to the 16th order. The tables presented below for each embodiment are the corresponding schematic parameter and aberration curves, and the definitions of the tables are the same as Table 1 and Table 2 of the 1st embodiment. Therefore, an explanation in this regard will not be provided again.

2nd Embodiment

FIG. 3 is a schematic view of an image capturing unit according to the 2nd embodiment of the present disclosure. FIG. 4 shows, in order from left to right, spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 2nd embodiment. In FIG. 3, the image capturing unit includes the photographing optical lens assembly (its reference numeral is omitted) of the present disclosure and an image sensor 290. The photographing optical lens assembly includes, in order from an object side to an image side an aperture stop 200, a first lens element 210, a second lens element 220, a third lens element 230, a fourth lens element 240, a fifth lens element 250, a sixth lens element 260, an IR-cut filter 270 and an image surface 280, wherein the photographing optical lens assembly has a total of six non-cemented lens elements (210-260) with refractive power. There is an air gap in a paraxial region between every two of the first lens element 210, the second lens element 220, the third lens element 230, the fourth lens element 240, the fifth lens element 250 and the sixth lens element 260 that are adjacent to each other.

The first lens element 210 with positive refractive power has an object-side surface 211 being convex in a paraxial region thereof and an image-side surface 212 being concave in a paraxial region thereof. The first lens element 210 is made of plastic material and has the object-side surface 211 and the image-side surface 212 being both aspheric.

The second lens element 220 with negative refractive power has an object-side surface 221 being concave in a paraxial region thereof and an image-side surface 222 being concave in a paraxial region thereof. The second lens element 220 is made of plastic material and has the object-side surface 221 and the image-side surface 222 being both aspheric.

The third lens element 230 with negative refractive power has an object-side surface 231 being concave in a paraxial region thereof and an image-side surface 232 being convex in a paraxial region thereof. The third lens element 230 is made of plastic material and has the object-side surface 231 and the image-side surface 232 being both aspheric.

The fourth lens element 240 with positive refractive power has an object-side surface 241 being convex in a paraxial region thereof and an image-side surface 242 being concave in a paraxial region thereof. The fourth lens element 240 is made of plastic material and has the object-side surface 241 and the image-side surface 242 being both aspheric. The image-side surface 242 of the fourth lens element 240 has at least one convex shape in an off-axis region thereof.

The fifth lens element 250 with negative refractive power has an object-side surface 251 being concave in a paraxial region thereof and an image-side surface 252 being convex in a paraxial region thereof. The fifth lens element 250 is made of plastic material and has the object-side surface 251 and the image-side surface 252 being both aspheric.

The sixth lens element 260 with negative refractive power has an object-side surface 261 being convex in a paraxial region thereof and an image-side surface 262 being concave in a paraxial region thereof. The sixth lens element 260 is made of plastic material and has the object-side surface 261 and the image-side surface 262 being both aspheric. The image-side surface 262 of the sixth lens element 260 has at least one inflection point. The object-side surface 261 of the sixth lens element 260 has at least one concave shape and at least one convex shape in an off-axis region thereof. The object-side surface 261 of the sixth lens element 260 changes from the convex shape to the concave shape and then the convex shape in order from the paraxial region thereof toward the off-axis region thereof.

The IR-cut filter 270 is made of glass and located between the sixth lens element 260 and the image surface 280, and will not affect the focal length of the photographing optical lens assembly. The image sensor 290 is disposed on or near the image surface 280 of the photographing optical lens assembly.

The detailed optical data of the 2nd embodiment are shown in Table 3 and the aspheric surface data are shown in Table 4 below.

TABLE 3 2nd Embodiment f = 3.94 mm, Fno = 2.10, HFOV = 36.0 deg. Curvature Focal Surface # Radius Thickness Material Index Abbe # Length 0 Object Plano Infinity 1 Ape. Stop Plano −0.328  2 Lens 1 1.474 (ASP) 0.564 Plastic 1.535 55.7 2.88 3 30.585 (ASP) 0.082 4 Lens 2 −47.619 (ASP) 0.240 Plastic 1.650 21.4 −6.14 5 4.363 (ASP) 0.324 6 Lens 3 −6.628 (ASP) 0.283 Plastic 1.544 55.9 −15.13 7 −34.508 (ASP) 0.072 8 Lens 4 2.844 (ASP) 0.274 Plastic 1.544 55.9 6.91 9 11.292 (ASP) 0.388 10 Lens 5 −1.358 (ASP) 0.273 Plastic 1.640 23.3 −29.83 11 −1.576 (ASP) 0.183 12 Lens 6 1.943 (ASP) 0.800 Plastic 1.535 55.7 −16.45 13 1.364 (ASP) 0.600 14 IR-cut Plano 0.210 Glass 1.517 64.2 — filter 15 Plano 0.390 16 Image Plano — Note: Reference wavelength is 587.6 nm (d-line).

TABLE 4 Aspheric Coefficients Surface # 2 3 4 5 6 7 k = −1.1174E−01 −9.0000E+01 −9.0000E+01  2.4408E+00 1.0000E+00  1.0000E+00 A4 =  2.3343E−03 −5.2591E−02 −5.6655E−02  −5.6231E−03  −7.9029E−02  −1.8176E−01 A6 =  1.5832E−02  8.9665E−02 1.0678E−01 1.7869E−02 −8.1582E−02  −2.0343E−02 A8 = −8.4995E−03 −8.0261E−02 1.9565E−02 1.6787E−01 5.9892E−03  2.0276E−02 A10 = −3.9716E−02  4.6299E−03 −9.9791E−02  −2.1187E−01  7.8534E−02 −1.0907E−02 A12 =  8.5618E−02  3.6797E−02 3.9348E−02 1.6146E−01 9.4139E−03  5.6640E−03 A14 = −6.0384E−02 −3.3085E−02 1.5085E−02 −1.4103E−02  — — Surface # 8 9 10 11 12 13 k = −1.9808E+01 2.0000E+01 −9.8704E+00 −4.8227E−01 −2.0081E+01 −6.8425E+00 A4 = −6.8228E−02 1.5838E−03 −5.8078E−02  8.1628E−02 −1.7284E−01 −7.5084E−02 A6 = −1.4521E−02 −5.2170E−02  −3.2395E−02 −4.2407E−02  9.4319E−02  3.1007E−02 A8 = −4.4084E−02 5.1846E−04  9.8373E−02  3.3761E−02 −6.5496E−02 −1.4033E−02 A10 = −5.0412E−02 1.2389E−02 −4.5656E−02  9.8164E−03  3.8568E−02  4.4694E−03 A12 =  2.4422E−02 −7.0685E−03   5.4894E−03 −5.4144E−03 −1.2241E−02 −9.0502E−04 A14 =  6.8879E−02 2.0672E−03  1.8649E−03 −4.0957E−03  1.9015E−03  1.0231E−04 A16 = −6.7805E−02 — −1.9111E−03  1.4265E−03 −1.1537E−04 −4.8045E−06

In the 2nd embodiment, the equation of the aspheric surface profiles of the aforementioned lens elements is the same as the equation of the 1st embodiment. Also, the definitions of these parameters shown in the following table are the same as those stated in the 1st embodiment with corresponding values for the 2nd embodiment, so an explanation in this regard will not be provided again.

Moreover, these parameters can be calculated from Table 3 and Table 4 as the following values and satisfy the following conditions:

2nd Embodiment f [mm] 3.94 R8/(|R5| + |R6|) 0.27 Fno 2.10 Yk42/f5 −0.03 HFOV [deg.] 36.0 Yc62/f 0.34 V2/V5 0.92 |f1/f3| 0.19 R8/f 2.87 f5/f6 1.81 R8/R9 −8.32 SL/TL 0.93 R8/[f * (V1 − V5)] 0.09 TL/ImgH 1.60

3rd Embodiment

FIG. 5 is a schematic view of an image capturing unit according to the 3rd embodiment of the present disclosure. FIG. 6 shows, in order from left to right, spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 3rd embodiment. In FIG. 5, the image capturing unit includes the photographing optical lens assembly (its reference numeral is omitted) of the present disclosure and an image sensor 390. The photographing optical lens assembly includes, in order from an object side to an image side an aperture stop 300, a first lens element 310, a second lens element 320, a third lens element 330, a fourth lens element 340, a fifth lens element 350, a sixth lens element 360, an IR-cut filter 370 and an image surface 380, wherein the photographing optical lens assembly has a total of six non-cemented lens elements (310-360) with refractive power. There is an air gap in a paraxial region between every two of the first lens element 310, the second lens element 320, the third lens element 330, the fourth lens element 340, the fifth lens element 350 and the sixth lens element 360 that are adjacent to each other.

The first lens element 310 with positive refractive power has an object-side surface 311 being convex in a paraxial region thereof and an image-side surface 312 being concave in a paraxial region thereof. The first lens element 310 is made of plastic material and has the object-side surface 311 and the image-side surface 312 being both aspheric.

The second lens element 320 with negative refractive power has an object-side surface 321 being convex in a paraxial region thereof and an image-side surface 322 being concave in a paraxial region thereof. The second lens element 320 is made of plastic material and has the object-side surface 321 and the image-side surface 322 being both aspheric.

The third lens element 330 with positive refractive power has an object-side surface 331 being convex in a paraxial region thereof and an image-side surface 332 being convex in a paraxial region thereof. The third lens element 330 is made of plastic material and has the object-side surface 331 and the image-side surface 332 being both aspheric.

The fourth lens element 340 with positive refractive power has an object-side surface 341 being convex in a paraxial region thereof and an image-side surface 342 being concave in a paraxial region thereof. The fourth lens element 340 is made of plastic material and has the object-side surface 341 and the image-side surface 342 being both aspheric. The image-side surface 342 of the fourth lens element 340 has at least one convex shape in an off-axis region thereof.

The fifth lens element 350 with negative refractive power has an object-side surface 351 being concave in a paraxial region thereof and an image-side surface 352 being convex in a paraxial region thereof. The fifth lens element 350 is made of plastic material and has the object-side surface 351 and the image-side surface 352 being both aspheric.

The sixth lens element 360 with negative refractive power has an object-side surface 361 being concave in a paraxial region thereof and an image-side surface 362 being concave in a paraxial region thereof. The sixth lens element 360 is made of plastic material and has the object-side surface 361 and the image-side surface 362 being both aspheric. The image-side surface 362 of the sixth lens element 360 has at least one inflection point.

The IR-cut filter 370 is made of glass and located between the sixth lens element 360 and the image surface 380, and will not affect the focal length of the photographing optical lens assembly. The image sensor 390 is disposed on or near the image surface 380 of the photographing optical lens assembly.

The detailed optical data of the 3rd embodiment are shown in Table 5 and the aspheric surface data are shown in Table 6 below.

TABLE 5 3rd Embodiment f = 4.14 mm, Fno = 2.30, HFOV = 35.0 deg. Curvature Focal Surface # Radius Thickness Material Index Abbe # Length 0 Object Plano Infinity 1 Ape. Stop Plano −0.338  2 Lens 1 1.413 (ASP) 0.414 Plastic 1.544 55.9 4.55 3 2.949 (ASP) 0.076 4 Lens 2 2.266 (ASP) 0.240 Plastic 1.634 23.8 −7.32 5 1.460 (ASP) 0.175 6 Lens 3 3.615 (ASP) 0.612 Plastic 1.544 55.9 6.01 7 −32.000 (ASP) 0.155 8 Lens 4 3.647 (ASP) 0.254 Plastic 1.544 55.9 9.21 9 13.067 (ASP) 0.544 10 Lens 5 −1.131 (ASP) 0.313 Plastic 1.634 23.8 −42.92 11 −1.307 (ASP) 0.280 12 Lens 6 −28.027 (ASP) 0.900 Plastic 1.535 55.7 −5.23 13 3.146 (ASP) 0.400 14 IR-cut Plano 0.210 Glass 1.517 64.2 — filter 15 Plano 0.328 16 Image Plano — Note: Reference wavelength is 587.6 nm (d-line).

TABLE 6 Aspheric Coefficients Surface # 2 3 4 5 6 7 k = 1.2126E−01 −1.9127E+01 −3.3282E+01  −7.6690E+00  −4.2371E+01   1.0000E+00 A4 = −1.7910E−03  −5.0245E−02 −8.6563E−02  1.8064E−02 5.5124E−02 −1.6944E−01 A6 = 3.0643E−02  1.8947E−01 1.2076E−01 9.6196E−02 2.6276E−03  4.2489E−02 A8 = −4.5110E−02  −7.1721E−02 5.6691E−02 1.0864E−01 −1.6239E−02  −2.2318E−02 A10 = 1.1983E−02  1.7478E−03 −1.5720E−01  −2.6994E−01  2.5068E−02 −2.7766E−02 A12 = 9.3458E−02  4.0651E−02 6.7092E−02 1.1786E−01 1.8781E−03  2.4440E−02 A14 = −5.8316E−02  −4.9157E−03 5.6853E−03 5.7352E−02 — — Surface # 8 9 10 11 12 13 k = −4.5653E+01  9.4826E+00 −2.9310E+00 −6.5389E−01 −4.0353E+00 −1.6622E+01 A4 = −1.1484E−01 −1.6281E−02 −9.0271E−02  4.1455E−02 −1.6111E−01 −5.6268E−02 A6 = −1.1120E−01 −1.0223E−01 −8.7410E−03 −1.7099E−02  9.5554E−02  2.4745E−02 A8 = −5.6364E−02  2.1317E−02  1.1137E−01  3.3760E−02 −6.5222E−02 −1.2885E−02 A10 = −1.7965E−02  2.8186E−02 −4.7810E−02  8.7672E−03  3.8474E−02  4.4307E−03 A12 =  2.2094E−02 −1.9268E−03 −3.7282E−03 −5.6339E−03 −1.2281E−02 −9.1613E−04 A14 =  6.8712E−02 −3.7867E−03  1.0021E−03 −4.0762E−03  1.8974E−03  1.0173E−04 A16 = −6.0709E−02 — −4.9109E−04  1.4667E−03 −1.1305E−04 −4.6389E−06

In the 3rd embodiment, the equation of the aspheric surface profiles of the aforementioned lens elements is the same as the equation of the 1st embodiment. Also, the definitions of these parameters shown in the following table are the same as those stated in the 1st embodiment with corresponding values for the 3rd embodiment, so an explanation in this regard will not be provided again.

Moreover, these parameters can be calculated from Table 5 and Table 6 as the following values and satisfy the following conditions:

3rd Embodiment f [mm] 4.14 R8/(|R5| + |R6|) 0.37 Fno 2.30 Yk42/f5 −0.01 HFOV [deg.] 35.0 Yc62/f 0.28 V2/V5 1.00 |f1/f3| 0.76 R8/f 3.16 f5/f6 8.20 R8/R9 −11.55 SL/TL 0.93 R8/[f * (V1 − V5)] 0.10 TL/ImgH 1.67

4th Embodiment

FIG. 7 is a schematic view of an image capturing unit according to the 4th embodiment of the present disclosure. FIG. 8 shows, in order from left to right, spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 4th embodiment. In FIG. 7, the image capturing unit includes the photographing optical lens assembly (its reference numeral is omitted) of the present disclosure and an image sensor 490. The photographing optical lens assembly includes, in order from an object side to an image side, an aperture stop 400, a first lens element 410, a second lens element 420, a third lens element 430, a fourth lens element 440, a fifth lens element 450, a sixth lens element 460, an IR-cut filter 470 and an image surface 480, wherein the photographing optical lens assembly has a total of six non-cemented lens elements (410-460) with refractive power. There is an air gap in a paraxial region between every two of the first lens element 410, the second lens element 420, the third lens element 430, the fourth lens element 440, the fifth lens element 450 and the sixth lens element 460 that are adjacent to each other.

The first lens element 410 with positive refractive power has an object-side surface 411 being convex in a paraxial region thereof and an image-side surface 412 being concave in a paraxial region thereof. The first lens element 410 is made of plastic material and has the object-side surface 411 and the image-side surface 412 being both aspheric.

The second lens element 420 with negative refractive power has an object-side surface 421 being convex in a paraxial region thereof and an image-side surface 422 being concave in a paraxial region thereof. The second lens element 420 is made of plastic material and has the object-side surface 421 and the image-side surface 422 being both aspheric.

The third lens element 430 with positive refractive power has an object-side surface 431 being convex in a paraxial region thereof and an image-side surface 432 being convex in a paraxial region thereof. The third lens element 430 is made of plastic material and has the object-side surface 431 and the image-side surface 432 being both aspheric.

The fourth lens element 440 with negative refractive power has an object-side surface 441 being concave in a paraxial region thereof and an image-side surface 442 being concave in a paraxial region thereof. The fourth lens element 440 is made of plastic material and has the object-side surface 441 and the image-side surface 442 being both aspheric. The image-side surface 442 of the fourth lens element 440 has at least one convex shape in an off-axis region thereof.

The fifth lens element 450 with negative refractive power has an object-side surface 451 being concave in a paraxial region thereof and an image-side surface 452 being convex in a paraxial region thereof. The fifth lens element 450 is made of plastic material and has the object-side surface 451 and the image-side surface 452 being both aspheric.

The sixth lens element 460 with negative refractive power has an object-side surface 461 being convex in a paraxial region thereof and an image-side surface 462 being concave in a paraxial region thereof. The sixth lens element 460 is made of plastic material and has the object-side surface 461 and the image-side surface 462 being both aspheric. The image-side surface 462 of the sixth lens element 460 has at least one inflection point. The object-side surface 461 of the sixth lens element 460 has at least one concave shape and at least one convex shape in an off-axis region thereof. The object-side surface 461 of the sixth lens element 460 changes from the convex shape to the concave shape and then the convex shape in order from the paraxial region thereof toward the off-axis region thereof.

The IR-cut filter 470 is made of glass and located between the sixth lens element 460 and the image surface 480, and will not affect the focal length of the photographing optical lens assembly. The image sensor 490 is disposed on or near the image surface 480 of the photographing optical lens assembly.

The detailed optical data of the 4th embodiment are shown in Table 7 and the aspheric surface data are shown in Table 8 below.

TABLE 7 4th Embodiment f = 4.13 mm, Fno = 2.30, HFOV = 36.5 deg. Curvature Focal Surface # Radius Thickness Material Index Abbe # Length 0 Object Plano Infinity 1 Ape. Stop Plano −0.344  2 Lens 1 1.408 (ASP) 0.419 Plastic 1.544 55.9 4.26 3 3.214 (ASP) 0.085 4 Lens 2 2.370 (ASP) 0.240 Plastic 1.634 23.8 −5.76 5 1.381 (ASP) 0.148 6 Lens 3 3.121 (ASP) 0.623 Plastic 1.544 55.9 3.70 7 −5.269 (ASP) 0.193 8 Lens 4 −47.178 (ASP) 0.240 Plastic 1.544 55.9 −37.36 9 35.793 (ASP) 0.534 10 Lens 5 −1.095 (ASP) 0.298 Plastic 1.634 23.8 −20.04 11 −1.324 (ASP) 0.127 12 Lens 6 3.748 (ASP) 0.891 Plastic 1.530 55.8 −9.53 13 1.974 (ASP) 0.500 14 IR-cut Plano 0.210 Glass 1.517 64.2 — filter 15 Plano 0.340 16 Image Plano — — Note: Reference wavelength is 587.6 nm (d-line).

TABLE 8 Aspheric Coefficients Surface # 2 3 4 5 6 7 k = 3.1467E−01 −1.5461E+01 −3.0331E+01  −6.6980E+00  −2.1687E+01  −8.8719E+01 A4 = −1.1051E−02  −3.9185E−02 −9.6879E−02  2.4404E−02 6.9400E−02 −1.3587E−01 A6 = 4.4590E−02  1.9751E−01 1.3319E−01 8.4389E−02 1.2295E−02  1.4850E−02 A8 = −7.3014E−02  −6.9523E−02 6.9338E−02 1.0978E−01 −1.8062E−02  −2.3000E−02 A10 = 2.5003E−02 −1.8819E−02 −1.9691E−01  −2.6933E−01  1.7628E−02 −2.4537E−02 A12 = 9.3436E−02  4.0514E−02 6.7194E−02 1.1826E−01 2.0432E−03  2.4427E−02 A14 = −5.8320E−02  −4.9178E−03 5.6841E−03 5.7428E−02 — — Surface # 8 9 10 11 12 13 k = −6.1880E+01 −4.2992E+01 −4.5156E+00 −5.5643E−01 −7.0568E+01 −1.0718E+01 A4 = −1.5083E−01 −3.2635E−02 −9.6215E−02  4.8271E−02 −1.7960E−01 −6.0086E−02 A6 = −1.3804E−01 −8.2715E−02 −7.3156E−03 −3.7091E−02  9.6265E−02  2.6385E−02 A8 = −5.8529E−02  1.5211E−02  9.0877E−02  3.2445E−02 −6.5224E−02 −1.3446E−02 A10 =  8.1260E−03  1.7621E−02 −6.0520E−02  9.8039E−03  3.8467E−02  4.4744E−03 A12 =  2.1865E−02 −4.8225E−03 −3.4512E−03 −5.1224E−03 −1.2281E−02 −9.1118E−04 A14 =  6.8645E−02  1.6750E−03  4.1214E−03 −3.9495E−03  1.8986E−03  1.0148E−04 A16 = −6.0717E−02 — −5.6515E−04  1.4760E−03 −1.1246E−04 −4.7057E−06

In the 4th embodiment, the equation of the aspheric surface profiles of the aforementioned lens elements is the same as the equation of the 1st embodiment. Also, the definitions of these parameters shown in the following table are the same as those stated in the 1st embodiment with corresponding values for the 4th embodiment, so an explanation in this regard will not be provided again.

Moreover, these parameters can be calculated from Table 7 and Table 8 as the following values and satisfy the following conditions:

4th Embodiment f [mm] 4.13 R8/(|R5| + |R6|) 4.27 Fno 2.30 Yk42/f5 −0.02 HFOV [deg.] 36.5 Yc62/f 0.31 V2/V5 1.00 |f1/f3| 1.15 R8/f 8.66 f5/f6 2.10 R8/R9 −32.70 SL/TL 0.93 R8/[f * (V1 − V5)] 0.27 TL/ImgH 1.58

5th Embodiment

FIG. 9 is a schematic view of an image capturing unit according to the 5th embodiment of the present disclosure. FIG. 10 shows, in order from left to right, spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 5th embodiment. In FIG. 9, the image capturing unit includes the photographing optical lens assembly (its reference numeral is omitted) of the present disclosure and an image sensor 590. The photographing optical lens assembly includes, in order from an object side to an image side, a first lens element 510, an aperture stop 500, a second lens element 520, a third lens element 530, a fourth lens element 540, a fifth lens element 550, a sixth lens element 560, an IR-cut filter 570 and an image surface 580, wherein the photographing optical lens assembly has a total of six non-cemented lens elements (510-560) with refractive power. There is an air gap in a paraxial region between every two of the first lens element 510, the second lens element 520, the third lens element 530, the fourth lens element 540, the fifth lens element 550 and the sixth lens element 560 that are adjacent to each other.

The first lens element 510 with positive refractive power has an object-side surface 511 being convex in a paraxial region thereof and an image-side surface 512 being concave in a paraxial region thereof. The first lens element 510 is made of plastic material and has the object-side surface 511 and the image-side surface 512 being both aspheric.

The second lens element 520 with negative refractive power has an object-side surface 521 being convex in a paraxial region thereof and an image-side surface 522 being concave in a paraxial region thereof. The second lens element 520 is made of plastic material and has the object-side surface 521 and the image-side surface 522 being both aspheric.

The third lens element 530 with positive refractive power has an object-side surface 531 being convex in a paraxial region thereof and an image-side surface 532 being concave in a paraxial region thereof. The third lens element 530 is made of plastic material and has the object-side surface 531 and the image-side surface 532 being both aspheric.

The fourth lens element 540 with positive refractive power has an object-side surface 541 being convex in a paraxial region thereof and an image-side surface 542 being concave in a paraxial region thereof. The fourth lens element 540 is made of plastic material and has the object-side surface 541 and the image-side surface 542 being both aspheric. The image-side surface 542 of the fourth lens element 540 has at least one convex shape in an off-axis region thereof.

The fifth lens element 550 with negative refractive power has an object-side surface 551 being concave in a paraxial region thereof and an image-side surface 552 being convex in a paraxial region thereof. The fifth lens element 550 is made of plastic material and has the object-side surface 551 and the image-side surface 552 being both aspheric.

The sixth lens element 560 with negative refractive power has an object-side surface 561 being convex in a paraxial region thereof and an image-side surface 562 being concave in a paraxial region thereof. The sixth lens element 560 is made of plastic material and has the object-side surface 561 and the image-side surface 562 being both aspheric. The image-side surface 562 of the sixth lens element 560 has at least one inflection point. The object-side surface 561 of the sixth lens element 560 has at least one concave shape and at least one convex shape in an off-axis region thereof. The object-side surface 561 of the sixth lens element 560 changes from the convex shape to the concave shape and then the convex shape in order from the paraxial region thereof toward the off-axis region thereof.

The IR-cut filter 570 is made of glass and located between the sixth lens element 560 and the image surface 580, and will not affect the focal length of the photographing optical lens assembly. The image sensor 590 is disposed on or near the image surface 580 of the photographing optical lens assembly.

The detailed optical data of the 5th embodiment are shown in Table 9 and the aspheric surface data are shown in Table 10 below.

TABLE 9 5th Embodiment f = 5.02 mm, Fno = 2.23, HFOV = 39.0 deg. Curvature Focal Surface # Radius Thickness Material Index Abbe # Length 0 Object Plano Infinity 1 Lens 1 2.060 (ASP) 0.529 Plastic 1.544 55.9 4.93 2 8.048 (ASP) 0.055 3 Ape. Stop Plano 0.064 4 Lens 2 3.299 (ASP) 0.260 Plastic 1.640 23.3 −8.95 6 2.029 (ASP) 0.279 7 Lens 3 6.335 (ASP) 0.537 Plastic 1.544 55.9 18.01 8 17.377 (ASP) 0.302 9 Lens 4 5.807 (ASP) 0.333 Plastic 1.544 55.9 11.93 10 53.957 (ASP) 0.570 11 Lens 5 −1.224 (ASP) 0.321 Plastic 1.640 23.3 −17.91 12 −1.511 (ASP) 0.106 13 Lens 6 2.578 (ASP) 1.199 Plastic 1.535 55.7 −85.99 14 2.045 (ASP) 0.850 15 IR-cut Plano 0.280 Glass 1.517 64.2 — filter 16 Plano 0.447 17 Image Plano — Note: Reference wavelength is 587.6 nm (d-line).

TABLE 10 Aspheric Coefficients Surface # 1 2 4 5 6 7 k = −2.0366E−01 −5.5319E+01 −1.9581E+01  −5.4885E+00  −3.1304E+01 −9.0000E+01 A4 = −3.6354E−04 −3.5797E−02 −4.4343E−02  5.7821E−03  3.0933E−03 −4.5305E−02 A6 =  3.0786E−04  2.7681E−02 2.4879E−02 1.1516E−02 −2.6658E−03 −4.2178E−03 A8 = −2.8319E−03 −1.6344E−02 6.4890E−03 1.7957E−02 −8.1788E−04 −9.2149E−05 A10 = −3.5332E−03  2.2743E−03 −8.0064E−03  −1.6943E−02  −6.0806E−04 −4.3124E−03 A12 =  3.4277E−03  1.6894E−03 1.7962E−03 5.6654E−03 −6.0016E−05 −6.7102E−05 A14 = −1.3107E−03 −7.3837E−04 3.0641E−04 −4.9035E−04  — — Surface # 8 9 10 11 12 13 k = −5.3845E+00 −9.0000E+01 −4.5493E+00 −7.7734E−01 −2.3357E+01 −6.9756E+00 A4 = −5.7270E−02 −2.3108E−02 −2.6683E−02  4.8926E−02 −6.7736E−02 −2.9960E−02 A6 = −1.5112E−02 −1.3305E−02 −5.7253E−03 −7.7504E−03  2.0910E−02  6.9430E−03 A8 =  1.0872E−03 −2.0876E−04  1.2566E−02  3.4419E−03 −8.0577E−03 −1.7181E−03 A10 = −7.0494E−03  1.2351E−03 −3.3016E−03  5.5221E−04  2.5842E−03  2.9771E−04 A12 =  7.7652E−04 −1.8060E−04 −9.2402E−05 −1.9926E−04 −4.5096E−04 −3.3205E−05 A14 =  1.2503E−03  6.0636E−05  3.9841E−05 −8.1046E−05  3.8553E−05  2.0736E−06 A16 = −7.7574E−04 — −1.2306E−05  1.7141E−05 −1.2836E−06 −5.5033E−08

In the 5th embodiment, the equation of the aspheric surface profiles of the aforementioned lens elements is the same as the equation of the 1st embodiment. Also, the definitions of these parameters shown in the following table are the same as those stated in the 1st embodiment with corresponding values for the 5th embodiment, so an explanation in this regard will not be provided again.

Moreover, these parameters can be calculated from Table 9 and Table 10 as the following values and satisfy the following conditions:

5th Embodiment f [mm] 5.02 R8/(|R5| + |R6|) 2.28 Fno 2.23 Yk42/f5 −0.02 HFOV [deg.] 39.0 Yc62/f 0.36 V2/V5 1.00 |f1/f3| 0.27 R8/f 10.75 f5/f6 0.21 R8/R9 −44.08 SL/TL 0.90 R8/[f * (V1 − V5)] 0.33 TL/ImgH 1.53

6th Embodiment

FIG. 11 is a schematic view of an image capturing unit according to the 6th embodiment of the present disclosure. FIG. 12 shows, in order from left to right, spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 6th embodiment. In FIG. 11, the image capturing unit includes the photographing optical lens assembly (its reference numeral is omitted) of the present disclosure and an image sensor 690. The photographing optical lens assembly includes, in order from an object side to an image side, an aperture stop 600, a first lens element 610, a second lens element 620, a third lens element 630, a fourth lens element 640, a fifth lens element 650, a sixth lens element 660, an IR-cut filter 670 and an image surface 680, wherein the photographing optical lens assembly has a total of six non-cemented lens elements (610-660) with refractive power. There is an air gap in a paraxial region between every two of the first lens element 610, the second lens element 620, the third lens element 630, the fourth lens element 640, the fifth lens element 650 and the sixth lens element 660 that are adjacent to each other.

The first lens element 610 with positive refractive power has an object-side surface 611 being convex in a paraxial region thereof and an image-side surface 612 being concave in a paraxial region thereof. The first lens element 610 is made of glass material and has the object-side surface 611 and the image-side surface 612 being both aspheric.

The second lens element 620 with negative refractive power has an object-side surface 621 being convex in a paraxial region thereof and an image-side surface 622 being concave in a paraxial region thereof. The second lens element 620 is made of plastic material and has the object-side surface 621 and the image-side surface 622 being both aspheric.

The third lens element 630 with negative refractive power has an object-side surface 631 being convex in a paraxial region thereof and an image-side surface 632 being concave in a paraxial region thereof. The third lens element 630 is made of plastic material and has the object-side surface 631 and the image-side surface 632 being both aspheric.

The fourth lens element 640 with positive refractive power has an object-side surface 641 being convex in a paraxial region thereof and an image-side surface 642 being concave in a paraxial region thereof. The fourth lens element 640 is made of plastic material and has the object-side surface 641 and the image-side surface 642 being both aspheric. The image-side surface 642 of the fourth lens element 640 has at least one convex shape in an off-axis region thereof.

The fifth lens element 650 with negative refractive power has an object-side surface 651 being concave in a paraxial region thereof and an image-side surface 652 being convex in a paraxial region thereof. The fifth lens element 650 is made of plastic material and has the object-side surface 651 and the image-side surface 652 being both aspheric.

The sixth lens element 660 with negative refractive power has an object-side surface 661 being convex in a paraxial region thereof and an image-side surface 662 being concave in a paraxial region thereof. The sixth lens element 660 is made of plastic material and has the object-side surface 661 and the image-side surface 662 being both aspheric. The image-side surface 662 of the sixth lens element 660 has at least one inflection point. The object-side surface 661 of the sixth lens element 660 has at least one concave shape and at least one convex shape in an off-axis region thereof. The object-side surface 661 of the sixth lens element 660 changes from the convex shape to the concave shape and then the convex shape in order from the paraxial region thereof toward the off-axis region thereof.

The IR-cut filter 670 is made of glass and located between the sixth lens element 660 and the image surface 680, and will not affect the focal length of the photographing optical lens assembly. The image sensor 690 is disposed on or near the image surface 680 of the photographing optical lens assembly.

The detailed optical data of the 6th embodiment are shown in Table 11 and the aspheric surface data are shown in Table 12 below.

TABLE 11 6th Embodiment f = 5.42 mm, Fno = 2.00, HFOV = 36.0 deg. Curvature Focal Surface # Radius Thickness Material Index Abbe # Length 0 Object Plano Infinity 1 Ape. Stop Plano −0.474  2 Lens 1 2.022 (ASP) 0.598 Glass 1.566 71.2 5.65 3 4.904 (ASP) 0.141 4 Lens 2 2.648 (ASP) 0.260 Plastic 1.640 23.3 −22.39 5 2.149 (ASP) 0.433 6 Lens 3 7.184 (ASP) 0.441 Plastic 1.535 55.7 −29.90 7 4.851 (ASP) 0.239 8 Lens 4 4.486 (ASP) 0.338 Plastic 1.535 55.7 9.72 9 31.716 (ASP) 0.531 10 Lens 5 −2.105 (ASP) 0.500 Plastic 1.640 23.3 −67.52 11 −2.417 (ASP) 0.219 12 Lens 6 1.647 (ASP) 0.600 Plastic 1.535 55.7 −33.86 13 1.318 (ASP) 0.945 14 IR-cut Plano 0.284 Glass 1.517 64.2 — filter 15 Plano 0.755 16 Image Plano — Note: Reference wavelength is 587.6 nm (d-line).

TABLE 12 Aspheric Coefficients Surface # 2 3 4 5 6 7 k = −1.9454E−01 −3.4365E+01 −1.8018E+01 −7.3684E+00 −9.0000E+01 −5.5666E+01 A4 = −4.0201E−03 −4.0799E−02 −3.8771E−02 −4.1195E−04 −2.6124E−02 −4.7494E−02 A6 =  6.6900E−03  3.0040E−02  1.7196E−02  1.5929E−02  8.9167E−03 −3.0196E−03 A8 = −1.7924E−03 −1.2383E−02  8.7396E−03  1.6057E−02 −2.3954E−03  1.8307E−03 A10 = −4.6755E−03 −6.2176E−04 −7.2057E−03 −1.3652E−02  2.9599E−04 −3.6699E−03 A12 =  3.2793E−03  2.0248E−03  2.4097E−03  5.2244E−03  3.4786E−04  5.2309E−04 A14 = −7.9282E−04 −4.4647E−04 −1.6102E−04 −4.9035E−04 — — Surface # 8 9 10 11 12 13 k = −3.6915E+01 −9.0000E+01 −1.6191E+01 −2.3127E−01 −8.3127E+00 −5.3148E+00 A4 = −5.1583E−02 −3.5092E−02 −3.9013E−02  2.9613E−02 −8.1337E−02 −4.8530E−02 A6 = −1.0515E−02 −1.3584E−02 −1.2535E−02 −1.4666E−02  2.0604E−02  9.1282E−03 A8 = −3.6353E−03  2.6359E−03  1.1399E−02  3.4141E−03 −7.9195E−03 −1.8756E−03 A10 = −3.3355E−03  2.2706E−03 −2.7566E−03  8.3556E−04  2.6000E−03  2.9931E−04 A12 =  1.0393E−03 −1.9039E−04  2.8199E−04 −1.2978E−04 −4.5190E−04 −3.2573E−05 A14 =  1.4469E−03 −6.1503E−05  6.5687E−05 −7.5953E−05  3.8352E−05  2.0058E−06 A16 = −7.7574E−04 — −5.1286E−05  1.2138E−05 −1.2725E−06 −5.1547E−08

In the 6th embodiment, the equation of the aspheric surface profiles of the aforementioned lens elements is the same as the equation of the 1st embodiment. Also, the definitions of these parameters shown in the following table are the same as those stated in the 1st embodiment with corresponding values for the 6th embodiment, so an explanation in this regard will not be provided again.

Moreover, these parameters can be calculated from Table 11 and Table 12 as the following values and satisfy the following conditions:

6th Embodiment f [mm] 5.42 R8/(|R5| + |R6|) 2.64 Fno 2.00 Yk42/f5 −0.01 HFOV [deg.] 36.0 Yc62/f 0.29 V2/V5 1.00 |f1/f3| 0.19 R8/f 5.86 f5/f6 1.99 R8/R9 −15.07 SL/TL 0.92 R8/[f * (V1 − V5)] 0.12 TL/ImgH 1.53

7th Embodiment

FIG. 13 is a schematic view of an image capturing unit according to the 7th embodiment of the present disclosure. FIG. 14 shows, in order from left to right, spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 7th embodiment. In FIG. 13, the image capturing unit includes the photographing optical lens assembly (its reference numeral is omitted) of the present disclosure and an image sensor 790. The photographing optical lens assembly includes, in order from an object side to an image side, an aperture stop 700, a first lens element 710, a second lens element 720, a third lens element 730, a fourth lens element 740, a fifth lens element 750, a sixth lens element 760, an IR-cut filter 770 and an image surface 780, wherein the photographing optical lens assembly has a total of six non-cemented lens elements (710-760) with refractive power. There is an air gap in a paraxial region between every two of the first lens element 710, the second lens element 720, the third lens element 730, the fourth lens element 740, the fifth lens element 750 and the sixth lens element 760 that are adjacent to each other.

The first lens element 710 with positive refractive power has an object-side surface 711 being convex in a paraxial region thereof and an image-side surface 712 being concave in a paraxial region thereof. The first lens element 710 is made of plastic material and has the object-side surface 711 and the image-side surface 712 being both aspheric.

The second lens element 720 with negative refractive power has an object-side surface 721 being convex in a paraxial region thereof and an image-side surface 722 being concave in a paraxial region thereof. The second lens element 720 is made of plastic material and has the object-side surface 721 and the image-side surface 722 being both aspheric.

The third lens element 730 with positive refractive power has an object-side surface 731 being convex in a paraxial region thereof and an image-side surface 732 being concave in a paraxial region thereof. The third lens element 730 is made of plastic material and has the object-side surface 731 and the image-side surface 732 being both aspheric.

The fourth lens element 740 with positive refractive power has an object-side surface 741 being convex in a paraxial region thereof and an image-side surface 742 being concave in a paraxial region thereof. The fourth lens element 740 is made of plastic material and has the object-side surface 741 and the image-side surface 742 being both aspheric. The image-side surface 742 of the fourth lens element 740 has at least one convex shape in an off-axis region thereof.

The fifth lens element 750 with negative refractive power has an object-side surface 751 being concave in a paraxial region thereof and an image-side surface 752 being convex in a paraxial region thereof. The fifth lens element 750 is made of plastic material and has the object-side surface 751 and the image-side surface 752 being both aspheric.

The sixth lens element 760 with negative refractive power has an object-side surface 761 being convex in a paraxial region thereof and an image-side surface 762 being concave in a paraxial region thereof. The sixth lens element 760 is made of plastic material and has the object-side surface 761 and the image-side surface 762 being both aspheric. The image-side surface 762 of the sixth lens element 760 has at least one inflection point. The object-side surface 761 of the sixth lens element 760 has at least one concave shape and at least one convex shape in an off-axis region thereof. The object-side surface 761 of the sixth lens element 760 changes from the convex shape to the concave shape and then the convex shape in order from the paraxial region thereof toward the off-axis region thereof.

The IR-cut filter 770 is made of glass and located between the sixth lens element 760 and the image surface 780, and will not affect the focal length of the photographing optical lens assembly. The image sensor 790 is disposed on or near the image surface 780 of the photographing optical lens assembly.

The detailed optical data of the 7th embodiment are shown in Table 13 and the aspheric surface data are shown in Table 14 below.

TABLE 13 7th Embodiment f = 4.79 mm, Fno = 2.15, HFOV = 40.0 deg. Curvature Focal Surface # Radius Thickness Material Index Abbe # Length 0 Object Plano Infinity 1 Ape. Stop Plano −0.250  2 Lens 1 2.208 (ASP) 0.468 Plastic 1.535 56.3 5.64 3 7.625 (ASP) 0.069 4 Lens 2 2.560 (ASP) 0.260 Plastic 1.640 23.3 −9.61 5 1.736 (ASP) 0.273 6 Lens 3 4.643 (ASP) 0.570 Plastic 1.544 55.9 21.71 7 7.320 (ASP) 0.248 8 Lens 4 3.850 (ASP) 0.368 Plastic 1.544 55.9 8.04 9 31.070 (ASP) 0.673 10 Lens 5 −1.166 (ASP) 0.367 Plastic 1.614 25.6 −23.09 11 −1.423 (ASP) 0.030 12 Lens 6 2.549 (ASP) 1.202 Plastic 1.535 56.3 −62.97 13 1.980 (ASP) 0.800 14 IR-cut Plano 0.280 Glass 1.517 64.2 — filter 15 Plano 0.486 16 Image Plano — Note: Reference wavelength is 587.6 nm (d-line).

TABLE 14 Aspheric Coefficients Surface # 2 3 4 5 6 7 k = −1.5350E−01 −9.0000E+01 −1.6047E+01  −4.8990E+00  −2.2490E+01 −5.5895E+01 A4 =  1.5803E−03 −4.1860E−02 −4.0620E−02  3.2028E−03  1.4096E−02 −4.3951E−02 A6 = −6.7466E−03  3.3679E−02 1.8878E−02 8.7378E−03  9.9094E−04  3.8010E−03 A8 = −2.2964E−03 −1.6783E−02 8.3696E−03 1.5782E−02  1.0360E−03  1.7810E−03 A10 = −3.9256E−03  1.0731E−03 −6.2242E−03  −1.6039E−02  −4.2467E−04 −5.0986E−03 A12 =  5.5522E−03  2.8359E−03 1.6201E−03 5.0304E−03 −1.4073E−04  8.9205E−04 A14 = −2.1967E−03 −7.3836E−04 8.5628E−05 −3.4298E−04  — — Surface # 8 9 10 11 12 13 k = −3.9384E+00  2.0000E+01 −3.7644E+00 −8.0324E−01 −1.6625E+01 −5.6240E+00 A4 = −5.2839E−02 −1.3950E−02 −1.7834E−02  5.1101E−02 −6.9539E−02 −3.2627E−02 A6 = −3.3287E−03 −1.1583E−02 −9.8058E−03 −6.8961E−03  2.0970E−02  7.3856E−03 A8 = −8.6064E−04 −4.5097E−04  1.1222E−02  3.5678E−03 −8.0047E−03 −1.7413E−03 A10 = −5.8865E−03  8.3765E−04 −2.8526E−03  5.7303E−04  2.5886E−03  2.9843E−04 A12 =  8.3359E−04 −2.6000E−04  2.1140E−04 −1.9845E−04 −4.5130E−04 −3.3194E−05 A14 =  1.3074E−03  1.0683E−04  8.1720E−05 −8.1560E−05  3.8468E−05  2.0762E−06 A16 = −7.4555E−04 — −5.5907E−05  1.6416E−05 −1.2843E−06 −5.4614E−08

In the 7th embodiment, the equation of the aspheric surface profiles of the aforementioned lens elements is the same as the equation of the 1st embodiment. Also, the definitions of these parameters shown in the following table are the same as those stated in the 1st embodiment with corresponding values for the 7th embodiment, so an explanation in this regard will not be provided again.

Moreover, these parameters can be calculated from Table 13 and Table 14 as the following values and satisfy the following conditions:

7th Embodiment f [mm] 4.79 R8/(|R5| + |R6|) 2.60 Fno 2.15 Yk42/f5 −0.03 HFOV [deg.] 40.0 Yc62/f 0.39 V2/V5 0.91 |f1/f3| 0.26 R8/f 6.48 f5/f6 0.37 R8/R9 −26.64 SL/TL 0.96 R8/[f * (V1 − V5)] 0.21 TL/ImgH 1.52

8th Embodiment

FIG. 15 is a schematic view of an image capturing unit according to the 8th embodiment of the present disclosure. FIG. 16 shows, in order from left to right, spherical aberration curves, astigmatic field curves and a distortion curve of the image capturing unit according to the 8th embodiment. In FIG. 15, the image capturing unit includes the photographing optical lens assembly (its reference numeral is omitted) of the present disclosure and an image sensor 890. The photographing optical lens assembly includes, in order from an object side to an image side, an aperture stop 800, a first lens element 810, a second lens element 820, a third lens element 830, a fourth lens element 840, a fifth lens element 850, a sixth lens element 860, an IR-cut filter 870 and an image surface 880, wherein the photographing optical lens assembly has a total of six non-cemented lens elements (810-860) with refractive power. There is an air gap in a paraxial region between every two of the first lens element 810, the second lens element 820, the third lens element 830, the fourth lens element 840, the fifth lens element 850 and the sixth lens element 860 that are adjacent to each other.

The first lens element 810 with positive refractive power has an object-side surface 811 being convex in a paraxial region thereof and an image-side surface 812 being convex in a paraxial region thereof. The first lens element 810 is made of plastic material and has the object-side surface 811 and the image-side surface 812 being both aspheric.

The second lens element 820 with negative refractive power has an object-side surface 821 being convex in a paraxial region thereof and an image-side surface 822 being concave in a paraxial region thereof. The second lens element 820 is made of plastic material and has the object-side surface 821 and the image-side surface 822 being both aspheric.

The third lens element 830 with negative refractive power has an object-side surface 831 being concave in a paraxial region thereof and an image-side surface 832 being convex in a paraxial region thereof. The third lens element 830 is made of plastic material and has the object-side surface 831 and the image-side surface 832 being both aspheric.

The fourth lens element 840 with positive refractive power has an object-side surface 841 being convex in a paraxial region thereof and an image-side surface 842 being concave in a paraxial region thereof. The fourth lens element 840 is made of plastic material and has the object-side surface 841 and the image-side surface 842 being both aspheric. The image-side surface 842 of the fourth lens element 840 has at least one convex shape in an off-axis region thereof.

The fifth lens element 850 with negative refractive power has an object-side surface 851 being concave in a paraxial region thereof and an image-side surface 852 being convex in a paraxial region thereof. The fifth lens element 850 is made of plastic material and has the object-side surface 851 and the image-side surface 852 being both aspheric.

The sixth lens element 860 with negative refractive power has an object-side surface 861 being convex in a paraxial region thereof and an image-side surface 862 being concave in a paraxial region thereof. The sixth lens element 860 is made of plastic material and has the object-side surface 861 and the image-side surface 862 being both aspheric. The image-side surface 862 of the sixth lens element 860 has at least one inflection point. The object-side surface 861 of the sixth lens element 860 has at least one concave shape and at least one convex shape in an off-axis region thereof. The object-side surface 861 of the sixth lens element 860 changes from the convex shape to the concave shape and then the convex shape in order from the paraxial region thereof toward the off-axis region thereof.

The IR-cut filter 870 is made of glass and located between the sixth lens element 860 and the image surface 880, and will not affect the focal length of the photographing optical lens assembly. The image sensor 890 is disposed on or near the image surface 880 of the photographing optical lens assembly.

The detailed optical data of the 8th embodiment are shown in Table 15 and the aspheric surface data are shown in Table 16 below.

TABLE 15 8th Embodiment f = 3.90 mm, Fno = 2.10, HFOV = 37.3 deg. Curvature Focal Surface # Radius Thickness Material Index Abbe # Length 0 Object Plano Infinity 1 Ape. Stop Plano −0.254  2 Lens 1 1.722 (ASP) 0.497 Plastic 1.535 55.7 2.97 3 −18.671 (ASP) 0.030 4 Lens 2 2.848 (ASP) 0.240 Plastic 1.650 21.4 −5.55 5 1.538 (ASP) 0.372 6 Lens 3 −16.696 (ASP) 0.329 Plastic 1.544 55.9 −56.97 7 −36.436 (ASP) 0.091 8 Lens 4 3.603 (ASP) 0.271 Plastic 1.544 55.9 8.72 9 14.592 (ASP) 0.408 10 Lens 5 −1.239 (ASP) 0.262 Plastic 1.640 23.3 −28.58 11 −1.439 (ASP) 0.150 12 Lens 6 1.800 (ASP) 0.800 Plastic 1.535 55.7 −32.49 13 1.378 (ASP) 0.700 14 IR-cut Plano 0.210 Glass 1.517 64.2 — filter 15 Plano 0.366 16 Image Plano — Note: Reference wavelength is 587.6 nm (d-line).

TABLE 16 Aspheric Coefficients Surface # 2 3 4 5 6 7 k = −1.6336E−01 −9.0000E+01 −2.1530E+01  −4.3738E+00 −4.5828E+01  1.0000E+00 A4 = −2.4585E−04 −3.8698E−02 −6.6054E−02  −1.9218E−02 −2.4224E−03 −1.2018E−01 A6 =  7.9070E−03  1.2527E−01 1.1286E−01  1.6914E−02 −4.7136E−02 −2.5400E−02 A8 = −2.2649E−02 −1.3640E−01 5.5490E−03  1.8424E−01  1.9554E−02 −1.7427E−03 A10 = −3.6442E−02  2.2200E−02 −1.2983E−01  −2.9126E−01  2.1194E−02 −1.5484E−02 A12 =  9.4447E−02  4.5977E−02 5.0838E−02  1.5108E−01  1.2735E−03  2.6262E−03 A14 = −6.0384E−02 −3.3085E−02 1.5085E−02 −1.4103E−02 — — Surface # 8 9 10 11 12 13 k = −3.9928E+01 −5.9565E+01 −8.4299E+00 −5.9782E−01 −1.7581E+01 −6.9318E+00 A4 = −1.0935E−01 −6.1765E−02 −4.7680E−02  9.5635E−02 −1.7228E−01 −8.0022E−02 A6 = −3.5836E−02 −3.4996E−02 −3.4077E−02 −4.0333E−02  9.3605E−02  3.1328E−02 A8 = −3.2475E−02  1.8631E−02  9.3254E−02  3.1876E−02 −6.5615E−02 −1.3933E−02 A10 = −2.6346E−02  1.6854E−02 −4.6401E−02  8.9836E−03  3.8574E−02  4.4505E−03 A12 =  2.2113E−02 −6.4661E−03  4.9445E−03 −5.4993E−03 −1.2233E−02 −9.0614E−04 A14 =  6.3824E−02  2.2635E−04  2.0119E−03 −4.0338E−03  1.9029E−03  1.0233E−04 A16 = −6.7805E−02 — −1.5940E−03  1.4892E−03 −1.1577E−04 −4.8145E−06

In the 8th embodiment, the equation of the aspheric surface profiles of the aforementioned lens elements is the same as the equation of the 1st embodiment. Also, the definitions of these parameters shown in the following table are the same as those stated in the 1st embodiment with corresponding values for the 8th embodiment, so an explanation in this regard will not be provided again.

Moreover, these parameters can be calculated from Table 15 and Table 16 as the following values and satisfy the following conditions:

8th Embodiment f [mm] 3.90 R8/(|R5| + |R6|) 0.27 Fno 2.10 Yk42/f5 −0.02 HFOV [deg.] 37.3 Yc62/f 0.33 V2/V5 0.92 |f1/f3| 0.05 R8/f 3.74 f5/f6 0.88 R8/R9 −11.78 SL/TL 0.95 R8/[f * (V1 − V5)] 0.12 TL/ImgH 1.54

The foregoing image capturing unit is able to be installed in, but not limited to, an electronic device, including smart phones, tablet personal computers and wearable apparatus. According to the present disclosure, the fifth lens element and the sixth element both have negative refractive powers so that it is favorable for the principal point of the photographing optical lens assembly being positioned away from the image side of the photographing optical lens assembly so as to reduce the back focal length of the photographing optical lens assembly, thereby keeping a compact size thereof. Furthermore, it is favorable for evenly distributing the refractive power of the photographing optical lens assembly so as to avoid excessive incident angle of the light at the peripheral region of the image, thereby reducing stray light. Moreover, the image-side surface of the fourth lens element is concave in a paraxial region thereof so that it is favorable for balancing the focusing capabilities at the central region and the peripheral region so as to reduce the image difference between the central region and the peripheral region. When specific conditions are satisfied, it is favorable for improving the flatness of the image surface and reducing the astigmatism and the coma of the off-axis field.

The foregoing description, for the purpose of explanation, has been described with reference to specific embodiments. It is to be noted that TABLES 1-16 show different data of the different embodiments; however, the data of the different embodiments are obtained from experiments. The embodiments were chosen and described in order to best explain the principles of the disclosure and its practical applications, to thereby enable others skilled in the art to best utilize the disclosure and various embodiments with various modifications as are suited to the particular use contemplated. The embodiments depicted above and the appended drawings are exemplary and are not intended to be exhaustive or to limit the scope of the present disclosure to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. 

What is claimed is:
 1. A photographing optical lens assembly comprising, in order from an object side to an image side: a first lens element with positive refractive power having an object-side surface being convex in a paraxial region thereof; a second lens element having negative refractive power; a third lens element having positive refractive power; a fourth lens element having an image-side surface being concave in a paraxial region thereof; a fifth lens element with negative refractive power having an object-side surface being concave in a paraxial region thereof and an image-side surface being convex in a paraxial region thereof, wherein both of the object-side surface and the image-side surface of the fifth lens element are aspheric; and a sixth lens element with negative refractive power having an object-side surface being convex in a paraxial region thereof and an image-side surface being concave in a paraxial region thereof, wherein both of object-side surface and the image-side surface of the sixth lens element are aspheric, and the image-side surface of the sixth lens element has at least one inflection point; wherein the photographing optical lens assembly has a total of six lens elements, the photographing optical lens assembly further comprises an aperture stop located between an imaged object and the third lens element; wherein a curvature radius of the image-side surface of the fourth lens element is R8, a focal length of the photographing optical lens assembly is f, an axial distance between the aperture stop and an image surface is SL, an axial distance between the object-side surface of the first lens element and the image surface is TL, a focal length of the fifth lens element is f5, a focal length of the sixth lens element is f6, and the following conditions are satisfied: 0.3<R8/f; 0.65<SL/TL<1.2; and 0<f5/f6.
 2. The photographing optical lens assembly of claim 1, wherein the fourth lens element has an object-side surface being convex in a paraxial region thereof.
 3. The photographing optical lens assembly of claim 1, wherein the third lens element has an image-side surface being convex in a paraxial region thereof.
 4. The photographing optical lens assembly of claim 1, wherein the curvature radius of the image-side surface of the fourth lens element is R8, the focal length of the photographing optical lens assembly is f, an Abbe number of the first lens element is V1, an Abbe number of the fifth lens element is V5, and the following condition is satisfied: 0<R8/[f*(V1−V5)]<3.
 5. The photographing optical lens assembly of claim 1, wherein the focal length of the fifth lens element is f5, the focal length of the sixth lens element is f6, and the following condition is satisfied: 0.1<f5/f6<10.
 6. The photographing optical lens assembly of claim 1, wherein a curvature radius of an object-side surface of the third lens element is R5, a curvature radius of an image-side surface of the third lens element is R6, the curvature radius of the image-side surface of the fourth lens element is R8, and the following condition is satisfied: 0<R8/(|R5|+|R6|)<2.45.
 7. The photographing optical lens assembly of claim 1, wherein an axial distance between the first lens element and the second lens element is T12, an axial distance between the second lens element and the third lens element is T23, an axial distance between the third lens element and the fourth lens element is T34, an axial distance between the fourth lens element and the fifth lens element is T45, an axial distance between the fifth lens element and the sixth lens element is T56, and the following conditions are satisfied: 0<T12<T34<T23<T45; and 0<T12<T56<T23<T45.
 8. The photographing optical lens assembly of claim 1, wherein a vertical distance between non-axial critical point on the image-side surface of the sixth lens element and an optical axis is Yc62, the focal length of the photographing optical lens assembly is f, and the following condition is satisfied: 0.1<Yc62/f<0.7.
 9. The photographing optical lens assembly of claim 1, wherein an Abbe number of the second lens element is V2, an Abbe number of the fifth lens element is V5, and the following condition is satisfied: 0.70<V2/V5≦1.0.
 10. The photographing optical lens assembly of claim 1, wherein the image-side surface of the fourth lens element has at least one convex shape in an off-axis region thereof.
 11. The photographing optical lens assembly of claim 1, wherein the image-side surface of the fourth lens element has at least one critical point k, a projection of the critical point k on an optical axis is closer to the image side of the photographing optical lens assembly than an intersection of the image-side surface of the fourth lens element and the optical axis, a vertical distance between the critical point k on the image-side surface of the fourth lens element and the optical axis is Yk42, the focal length of the fifth lens element is f5, and the following condition is satisfied: −1.0<Yk42/f5<0.
 12. An image capturing unit, comprising: the photographing optical lens assembly of claim 1; and an image sensor, wherein the image sensor is disposed on the image side of the photographing optical lens assembly.
 13. An electronic device, comprising: the image capturing unit of claim
 12. 14. A photographing optical lens assembly comprising, in order from an object side to an image side: a first lens element with positive refractive power having an image-side surface being concave in a paraxial region thereof; a second lens element with negative refractive power having an image-side surface being concave in a paraxial region thereof; a third lens element; a fourth lens element having an image-side surface being concave in a paraxial region thereof; a fifth lens element having negative refractive power, wherein both of an object-side surface and an image-side surface of the fifth lens element are aspheric; and a sixth lens element with negative refractive power having an image-side surface being concave in a paraxial region thereof, wherein both of an object-side surface and the image-side surface of the sixth lens element are aspheric, and the image-side surface of the sixth lens element has at least one inflection point; wherein the photographing optical lens assembly has a total of six lens elements, the photographing optical lens assembly further comprises an aperture stop located between an imaged object and the second lens element, an air gap in a paraxial region is located between every two of the first lens element, the second lens element, the third lens element, the fourth lens element, the fifth lens element and the sixth lens element that are adjacent to each other; wherein a curvature radius of the image-side surface of the fourth lens element is R8, a focal length of the photographing optical lens assembly is f, an axial distance between the aperture stop and an image surface is SL, an axial distance between an object-side surface of the first lens element and the image surface is TL, an Abbe number of the second lens element is V2, an Abbe number of the fifth lens element is V5, and the following conditions are satisfied: 0.3<R8/f; 0.85<SL/TL<1.2; and 0.70<V2/V5≦1.0.
 15. The photographing optical lens assembly of claim 14, wherein the second lens element has an object-side surface being convex in a paraxial region thereof.
 16. The photographing optical lens assembly of claim 14, wherein the fourth lens element has positive refractive power.
 17. The photographing optical lens assembly of claim 14, wherein the curvature radius of the image-side surface of the fourth lens element is R8, the focal length of the photographing optical lens assembly is f, and the following condition is satisfied: 5.0<R8/f.
 18. The photographing optical lens assembly of claim 14, wherein the axial distance between the object-side surface of the first lens element and the image surface is TL, a maximum image height of the photographing optical lens assembly is ImgH, and the following condition is satisfied: TL/ImgH<2.0.
 19. The photographing optical lens assembly of claim 14, wherein the curvature radius of the image-side surface of the fourth lens element is R8, the focal length of the photographing optical lens assembly is f, an Abbe number of the first lens element is V1, the Abbe number of the fifth lens element is V5, and the following condition is satisfied: 0<R8/[f*(V1−V5)]<3.
 20. The photographing optical lens assembly of claim 14, wherein the curvature radius of the image-side surface of the fourth lens element is R8, a curvature radius of the object-side surface of the fifth lens element is R9, and the following condition is satisfied: −19<R8/R9<0.
 21. The photographing optical lens assembly of claim 14, wherein a central thickness of the first lens element is CT1, a central thickness of the second lens element is CT2, a central thickness of the third lens element is CT3, a central thickness of the fourth lens element is CT4, a central thickness of the fifth lens element is CT5, a central thickness of the sixth lens element is CT6, and the following conditions are satisfied: CT2, CT4, CT5<CT1, CT3; and CT1, CT3<CT6.
 22. The photographing optical lens assembly of claim 14, wherein a focal length of the first lens element is f1, a focal length of the third lens element is f3, and the following condition is satisfied: 0.1<|f1/f3|.
 23. The photographing optical lens assembly of claim 14, wherein the object-side surface of the sixth lens element is convex in a paraxial region thereof, the object-side surface of the sixth lens element has at least one concave shape and at least one convex shape in an off-axis region thereof, and the object-side surface of the sixth lens element changes from the convex shape to the concave shape and then the convex shape in order from the paraxial region thereof toward the off-axis region thereof.
 24. The photographing optical lens assembly of claim 14, wherein the image-side surface of the fourth lens element has at least one critical point k, a projection of the critical point k on an optical axis is closer to the image side of the photographing optical lens assembly than an intersection of the image-side surface of the fourth lens element and the optical axis, a vertical distance between the critical point k on the image-side surface of the fourth lens element and the optical axis is Yk42, the focal length of the fifth lens element is f5, and the following condition is satisfied: −1.0<Yk42/f5<0. 